James w



(No Model.)

J. W. EASTON.

DYNAMO ELECTRIC MACHINE.

No. 383,113. Patented May 22, 1888.

q/qli imeoo/w, gM/u m/vbm UNITED STATES PATENT JAMES XV, EASTON, OF NEW YORK, N. Y,

DYNAMO SLECTRiG MACE-NE,

SPECIFICATION forming part of Letters Patent No. 383,113, dated May 22, 188$,

(No model.)

To aZZ whom it may concern.-

Be it known that 1, JAMES W. Easron', a subject of the Queen of GreatBritain, residing inNew York, in the county and State of New York, have invented certain new and useful Improvements in Dynamo-Electric Machines, of which the following is a specification.

The invention relates to the construction of electric generators and motors.

The invention consists, in general terms, in providing the armature with a field-magnet having poles of opposite character presented to different longitudinal portions of the armature and upon opposite sides thereof. The field-magnet may be constructed and wound in any convenient manner for securing poles of opposite character at proper points. The

so-called Siemens consequent-pole type of field-magnet may be adopted; but the posi tions of the two poles are such that they are not directly opposite each other, but are staggered or in different longitudinal planes.

In an application filed by me February 6, 1885, Serial No. 155,072, there are described certain constructions which are herein clai medw The accompanying drawing is a side eleva tion of a machine embodying the features of the invention,

Referring to the figure, A represents a ringarmature wound and mounted,in any convenient well-known n1anner,upon a shaft, 13; but it will be understood that the precise form of armature here shown is not always essential, and the type may be varied as found advantageous. This armature revolves within a field created by the field-niagnet F. This field-magnet is wound with coils n a" and ss and it is provided with polar extensions N and S These, respective] y, receive north and south polarity by reason. of currents traversing the several coils. The poles N and S, instead of being diametrically opposite each other, as in the usual construction of electric generators, are here diagonally arranged, so that while the pole N confronts one end of the armature the pole S confronts the other end.

By reason of this construction an armature of.

suitable length may be employed in connection with fieldemagnct poles which are narrow, and which'thus concentrate their lines of force upon small areas.

It is well known that, thecreticaily, an armature should be of as great length as pos sible and of small diameter, so that the core and the wire upon it may be in close proxiiniity to the poles, and the surface of the armature may be as great as possible for the purpose of radiating heat, and in the case of the Siemens armature that the proportion of idle wire at the ends of the armature shall be as small as possible; but such construction has been found to be disadvantageous in machines having lieldmagnets of the usual form, for the reason that the pole-pieces of the fieldinagnets have been made of a width equal to the length of the armature, and thus the magnetism is too greatly diffused and not suffi ciently concentrated upon the armature. By the construction'here adopted it will be seen that the core of a comparatively long armature is placed or revolves in a more intense field.

I claim as my invention- 1. The combination, with the arn'iature ofa dynamo electric machine, of a consequent pole field-magnet having its poles presented to different points in the length of said armature,each convolution of the coils ofsaid armature extending across the faceiof each of the field-magnet poles.

2. The combination,with the armature of a dynamo electric machine, of a field -n;1agnet having two poles facing the axis of the armature and presented to said armature at points diagonally opposite with reference to its axis, the separate convolntiens of the armature coils extending through the field of each pole.

8. In a dynamo'electric machine, the combination, with a ring-armature, of pole-pieces of opposite character presented to theperiphcry of the armature at different points in its length,the separate convolutions of the armature-coils extending across the face of each polepieee.

4. In a dynamoeleetric machine, the combination of a single continuous core of softiron Wire wound upon the same,forrning a cylindrical armature, and a ficldmagnet having consequent poles located in differenttrans In testimony whereof I have hereunto sub- 10 verse planes with reference to the axis of the scribed my name this 8th day of March, A. armature. D. 1887.

5. In an electric machine, the combination 5 of a continuous armature-core, its axis, wire JAMES W. EASTON.

' wound upon said core parallel with said axis,

and two field-magnet poles presented to difi'er- Witnesses: ent points in the length of the armature and DANL. W. EnGEooMB,

upon opposite sides thereof. CHARLES A. TERRY. 

